Convert image to printable ASCII with Python

我上大学那时还没有喷墨和激光打印机，只有9针/16针的针式打印机，只能打印ASCII字符，不能打印图像。有很酷的程序把图像转换成ASCII符。Google可以找到很多这类程序，如：

https://github.com/qeesung/image2ascii

https://github.com/uvipen/ASCII-generator

https://github.com/LazoCoder/Image-To-ASCII

这里share一个我写的比较简单的程序 (font file can be downloaded from fonts.google.com: hhttps://fonts.google.com/specimen/Courier+Prime?query=courier)：

import tkinter

from tkinter import filedialog

from PIL import Image, ImageFont

def create_char_map():

characters = " !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~"

weights = []

font_name = "Courier_Prime/CourierPrime-Regular.ttf"

font_size = 16 # px

font_color = "#000000" # HEX Black

font = ImageFont.truetype(font_name, font_size)

max_weight = 0

# Loop through the characters needed and save to desired location

for character in characters:

# Get text size of character

width, height = font.getsize(character)

pix = font.getmask(character)

weight = 0

for y in range(len(pix)//width): # the actual row might be smaller than hegith

for x in range(width):

weight += pix[x+width*y]

weights.append(weight)

if weight>max_weight: max_weight = weight

# uniform the weight to 0~256*3-1

char_map = {767-int(w*767/max_weight):ch for (w, ch) in zip(weights, characters)}

# for revert image: char_map = {int(w*767/max_weight):ch for (w, ch) in zip(weights, characters)}

return char_map

def get_pixmap(path):

im = Image.open(path)

print('Original: ' + str(im.size))

size = 320

if im.size[0] > size:

resized_image = im.resize((size, int(size * im.size[1] / im.size[0])))

pixmap = resized_image.load()

pixmap_size = resized_image.size

print('Resized: ' + str(pixmap_size))

else:

pixmap = im.load()

pixmap_size = im.size

return pixmap, pixmap_size

 

def getchar(rgb_sum):

for i in range(1, len(char_keys)):

if rgb_sum<char_keys[i]:

if char_keys[i]+char_keys[i-1]>rgb_sum*2: i=i-1

break

return char_map[char_keys[i]]

def main():

#return

root = tkinter.Tk()

root.withdraw()

fin=filedialog.askopenfilename()

if(fin):

pixmap, pixmap_size = get_pixmap(fin)

file = open('output.txt', 'w')

for y in range(0, pixmap_size[1]-1, 2):

line=''

for x in range(pixmap_size[0]):

# merge two line into one printed line to keep a better ratio

rgb_sum = (pixmap[x, y][0] + pixmap[x, y][1] + pixmap[x, y][2] +

 pixmap[x, y+1][0] + pixmap[x, y+1][1] + pixmap[x, y+1][2])>>1

line+=getchar(rgb_sum)

file.write(line+'\n')

file.close()

if __name__=="__main__":

char_map = create_char_map()

char_keys = sorted(char_map)

main()